Method of making lacteal food products



new no. za m 2,465,907

um'rao sraras PATENT orrice Company, San Francisco, Calm, a corporation oi California a r No Drawing. Application June 6, 1945, Serial No. 807,035

I s Clainu. 99-54) This invention relates to methods for heat products that are incompletely dehydrated, there treating milk products while preserving the natis no deposition of .calcium phosphates on storage,

- ural taste and color of the starting material. and whatever precipitation of lactose, ii any,

The invention further pertains to novel milk that may occur on storage, takes the form of line products distinguished by stability on storage crystals that are easily resuspended by agitation.

and by capacity of being easily reconstituted to Our novel method includes the step of carryiorm dispersions that closely resemble natural ing out whatever heat treatment in the liquid milk products. phase that may be required for sterilization, for

It is known that certain disadvantages and concentration, or for prevention of rancidity, in diillculties attend the heat treatment and, in the absence of a major portion of the mineral particular, the sterilization and the dehydration, and acid content of the original milk from which whether complete or incomplete, of liquid lacteal the final products are derived. In the preparaproducts containing substantial amounts of fat, tion of partially dehydrated products or merely lactose and protein. Partially dehydrated milk sterilized products,in particular, in the preparaproducts. such as ordinary condensed milk, have tion of canned condensed milk, we provide a a tan color that has been attributed to caramelliquid concentrate of the fatty constituents of ization, as well as a noticeable cooked or stale milk, such as cream. We also provide a deflavor, both due to exposure to elevated temperaiatted milk product containing major proportions tures during heating incident to pasteurization. of the lactose and protein content of milk, for sterilizationor concentration of the milk or the example, whey, and remove a substantial portion like.'-.- v0n storage of such partially dehydrated of the mineral and acid constituents from such milk products, an unsightly brown coloration a defatted milk product. The fat concentrate sometimes occursp Formation of deposits of caland the defatted product are then. thoroughly cium phosphates or of coarse, grainy or sandy commingled, as by a homogenizing step, and the lactose crystals is not unusual. Precipitation of '25 resulting mixture is subjected to whatever heat calcium phosphates (milk stone"), even during treatment may be required for sterilization, conthe concentration or evaporation. is quite comcentration and prevention of rancidity on stormon'. Yet some form of heat treatment is an ab- 9 age. If desired, the cream or the like may be heat solute necessity in the manufacture of liquid treated before the homogenizing step to stabilize milk productions on this order in order to insure the fat against oxidation or other deterioration sterility and to prevent rancidity on storage due leading to rancidity. Either or both of the cream .to o'g'lidation or other form of deterioration of and the demineralized skim milk may be concenthe fat content of the milk product. trated prior to the ho o enizin step- Similar troubles are encountered in the prepa- For the Preparation m dried milk pr ration of completely dehydrated milk products, 5 ucts, the concentrated product described in the as by spray dying or drum dying. Such complete preceding paragraph may be employed. dehydration is conventionally preceded by For the preparation of spr y ie Products. evaporation or concentration tending to efiect we provide a concentrate of milk fat, such as 'caramelization, development of a cooked or stale cream, and heat treat the same to stabilize the flavorand precipitation of calcium phosphates. 4 fat against development of rancidity. We also Like .disadvantages attend drum drying. Spray provide a defatted liquid milk concentrate condrying without previous concentration yields a taining major portions of the protein and lactose product that often turns rancid on storage. content from original milk, such as whey, remove Spray dried milk products containing protein and a substantial portion of the minerals and acids lactose turn brown, on storage, whether or not 4 from said defatted product, combine the fat conprepared from previously concentrated milk or centrate and the defatted, demineralized, dewhey. Neutralization of any acidity noticeable, acidified milk product, and, preferably after a for instance, in whey, does not prevent objectionpartial dehydration, spray dry the resulting mixable browning on' storage. ture.

We have now invented a method for preparing Our preferred method of removing minerals from liquid lacteal products novel compositions and acid from the defatted milk products to be that are distinguished by little or no cooked or blended with the milk fat concentrate (as disstale flavor, practically no carmelization, and abclosed hereinabove), includes the step of consence or reduction of brown coloration or rancidtacting whey or the like with suitable ion exity on storage. In the case oi those of our novel change and/or absorbent media. For instance,

c eapo:

whey may be contacted with a decationizlng medium to lower its pH value, for example, to below 2.0, and then contacted with a deacidifying (acid absorbent) medium to raise its pHvalue, for example, to about 6.0 to 7.5. Alternately sufficient proportions of the whey tobe demineralized can be admixed with a cation exchange medium and, after removal of the cation exchange medium, the product can be admixed with a deacidifier. Repeated successive treatment with a decationizer and a deacidifier can be carried out until the desired reduction in the mineral content is obtained. Generally, the ash content should be reduced at least to 3%. Preferably, the ash content of the total solids in the whey should be reduced to 2.0% or less.

Other means of treatment with ion exchangers and deacidiflers will be apparent and include, for instance, alternate percolation of whey or the like through decationizlng and deacidifying media, in repeated cycles, without bringing the pH value to the isoelectric point of the whey protein, whereby precipitation of such protein is avoided.

It is therefore an important object of the present invention to provide novel lacteal products characterized by freedom from rancidity and objectionable discoloration on storage, by taste and color essentially like natural milk products, and, in the case of liquid compositions, by absence of objectionable deposits of calcium phosphates and of grainy, sandy lactose particles.

Another object of this invention is to provide methods for heat treating milk products in the liquid phase without effecting caramelization or development of a cooked or stale flavor.

Still another object of the invention is to provide methods for the prevention of objectionable brown discoloration on storage of sterilized or more or less completely dehydrated milk products.

Another object of the present invention is to rovide methods for heat treatment of milk products in the absence of a substantial amount of the mineral and acid content of the original milk material.

' Other and further objects and featuresof the present invention will become apparent to those skilled in the art from the following description and appended claims.

An essential step in our methods is that of removing a substantial portion of the mineral and acid content of a liquid defatted milk product, such as whey, prior to any exposure to an elevated temperature. Such a demlneralization and deacidiflcation may be carried out concurrently in a manner described hereinbelow as applied speciflcally to whey.

Ordinary whey obtained, for instance, by rennet treatment of cow's milk may be passed through a bed of or otherwise contacted with a decationizing medium capable of replacing metal ions with hydrogen ions, such as the decation izing media disclosed in the article by Robert J. Myers et al., on pages 697-706 in volume 33 (1941), of Industrial and Engineering Chemistry." The resinous decationizlng media are particularly suitable. Preferably the rate of flow of the whey through the decationizlng medium is so regulated that the ellluent has a pH of 2.0 or less. The direction of flow is preferably upwardly through the medium, in order to disperse said medium and thereby prevent entrapment of particulate matter.

After exhaustion, the decationizlng. medium may be revivifled by treatment with a dilute acid. for instance, dilute hydrochloric acid.

The decationized whey may then be passed through a bed of, or otherwise contacted with, a deacidifying medium capable of absorbing acids such as one of the deanionizing or, more properly, deacidifying absorbent media disclosed in the above identified article by Robert J. Myers et al. Resinous deacidifying media are particularly suitable. Preferably the rate of flow of decationized whey through the deacidifying medium is regulated so that the eilluent has a pH value of from 6.0 to 7.5. The direction of flow should be upwardly through the medium, to flush away any precipitate of protein material into a zone ofv higher pH conditions where the protein is redissolved.

After exhaustion, the deacidifying medium may be revivified by treatment with a dilute alkali solution, for instance, a dilute solution of sodium hydroxide.

It should be understood that a similar reduc-' tion of ash content can be obtained by repeated cycles involvingsuiflcient contacts with a decationizing medium and a deacidifying medium, in which cycles the initial reduction of pH value is carried out only, for example, to a value of about 3.8. In other words, the ash removal is distributed between a plurality of cycles, and the whey is not exposed to a very low pH.

The demineralized whey obtained by percolating whey through a decationizlng and deacidifying media has a total solids content of which only about 3.0% or less may be ash. The remainder of the total solids content consists principally of lactose and 11.5% non-casein protein.

For combination with whey demineralized and deacidified as described hereinabove to a suitable ash content, for instance, 3% or less (preferably 2% or less) of the.total solids content, we provide a milk fat concentrate, such as cream that may have a 12.07% butterfat content. This fat concentrate is heat treated at pasteurization temperature or higher (preferably at 200 to 300 E), if the final mixture is-to be spray dried, in order to prevent development of rancidity in the spray dried product. Examples of such heat treatments are: 300 F. for about /2 minute; 250 F. for about 3 minutes; 200 F. for from 5 to 10 or more minutes. Methods and devices for carrying out such heat treatmentare available to those skilled in the art. If the final product is to be only sterilized or only to be partially dehydrated, or drum dried, the above mentioned heat treatment is optional.

The demineralized and deacidified whey is commingled with the eventually heat treated milk fat concentrate, as by a homogenizing step, optionally after a concentration of one or both of the two ingredients of the mixture. The mixture thus obtained, if intended for spray drying,

is preferably, but not necessarily, concentrated,

for instance, to a 20 to 50% total solids content,

by any conventional method. The final spray drying is carried out in any suitable manner and yields a white, relatively non-hygroscopic powder that is extremely easily dispersible in water. 0n storage, this powder will not turn rancid and will not develop an objectionable brown discoloration.

If the homogenized mixture is only to be sterilized or only to be concentrated, as for canning purposes, the latter procedures are carried out by any suitable conventional method to-yield a sterile concentrate free from brown discoloration Q and commingle this whey-with 282 parts by weight of bovine cream containing l2.0'l%.but-' terfat. The solids content of suchcream is calculated as follows:

Cream-12.07% lot The composition of the resulting blend will be apparent from the following table: I

Nonweiaht Casein Fat an: Solids Protein mum toes 1 Cream; an 46.0 M 1.80 9.51 28.0 .01 Whsy.. 1.0m sac cs4 41.50. 1.10

Total i0l.6 M 8.20 51.01 can 17 -Asdisclosedingreaterdetailinourcopending application entitled Novel lact'eal products and methods of making the same." SerialNo. 507,084, filed June 6, 1945, the deminerahsed and deacidifled ingredient of the mixtures forming one stage in the preparation of the products of the present invention contains substantially the total lactose content of the original whey or skim milk in unchanged form. sether with the albumin content of thewhey in a modified form which, although still easily and completely dispersible in water. contains relatively a larger fraction precipitated, by trichloracetic acid and is relatively more insoluble at a pH of 4.60 but unchanged with respect to solubility in saturated sodium sulfate solution. For other changes in the composition of lacteal products on treat- ;ment with decationizing and deacidiiying media, reference ,is made to said copending application, which also oifers an explanation for the advantages flowing from the changed composition.

It is possible, by the methods of the present invention, to prepare from bovine milk lacteal products not heretofore available. We can. for instance, prepare a substantial duplicate of human milk that is characterised by excellent keeping qualities and freedom from cooked or stale odors and that will not turn rancid or brown on storage.

In preparing a duplicate of human milk, we

can take 1000 parts by weight 0! demineralized and deacidifled bovine whey with an ash content amounting to 2% oi the total whey solids When the composition of the solids content of the resulting synthesized human milk is recalon the basis of 100%, the following composition is obtained:

Synthesized Human mu: mg}? 5%,

12.50 mm 0. s: as: 1. 01 8.10 1.0:; so. as 3. 45 27. 00 ca 2.15

For comparison. the average analysis of human milk is tabulated as follows: a

I Per cent Per cent Human Milk Average Analysis Liquid y 12. 1(1). (1) 0.68 s. 4 1. 02 s. z 7. 00 50.0 s. so can 0. so 2. 4

It is clear from this table that the synthesized human milk of the present invention has almost the identical composition as human milk.

Cow's milk. on the other hand, has a widely variant composition, -as indicated by the following table:

Per, cent Per cent Cow's Milk Liquid Dry is The liquid mixture prepared as described heretios of 1:1, 1:2 or 1:3, to form a reconstituted liquid product having the same total solids content and composition as mothers milk.

Regardless of which method of those disclosed hereinabove may be employed, the novel infant's food preparations duplicating mother's milk provided by the present invention are far superior for dietetic purposes to natural cow's milk or to any other products heretofore prepared from cow's milk.

Many details of method and composition may' be varied within a wide range without departing from the principles of this invention,.and it is, therefore, not our purpose to limit the patcut granted on this invention otherwise than v necessitated by the scope of the appended claims.

We claim as our invention: 1. The method of preparing a stable heat ,treated bovine milk product suitablefor infant feeding and free from cooked or stale flavors which comprises heat treating-a fat concentrate of bovine milk at least to pasteurization temperatures for a period oftime sufficient to stabilize the fat content thereofagainst. rancidity, contactin with resinous cation and anion exchange mediums a liquid whey containing lactose, ash

forming constituents, acid, milk protein and complex milk. protein derivative decomposition products forming a part of the total assayable nitrogen of the whey and thereby reducing the content of ash forming constituents of the whey and the content of said decomposition products with an accompanying reductiorr in assayable total nitrogen. and thereby also modifying the protein content of the whey in such a manner that when the treated liquid whey is spray dried it forms a powder which is-readily redispersible in water, and thereafter com- -minglin said heat treated fat concentrate and said thus treated whey in a ratio producing in the resulting mixture the same proportions of fat, lactose, casein protein, noncasein protein, and ash present in human milk. 2; The method of preparing a heat 'treated'liquid milk concentrate free from cooked or stale flavors and capable of prolongedstorage without "development of rancidity. or of objectionable brown discoloration and without precipitation of calcium phosphate or of coarse, sandy, or grainy lactose particles which comprises heat treating cream at from 200 to 300 F. for a time sufflcient to stabilize its fat content against rancid- 'ity, contacting whey containing lactose, ash forming constituents, acid, milk protein and complex milk protein derivative decomposition products .forming a part of the total assayable nitrogen of the material with a decationizing resinous .medium and replacing metal ions in saidwli'ey with hydrogen ions until the pH of said whey-is reduced at least-to 2, subsequently contacting said whey with a deacidifying resinous medium and absorbing acids formed by said replacement of said metal ionsby hydrogen ions until the pH 01' said whey is-raised to a value between fi and 7.5 and thereby reducing the content of ash forming constituents of the material and the content ofsaid decomposition products with an accompanying reduction in assayable total nitrogen and thereby also modifying the protein content ofjthe wheyto increase thefractlon thereof precipitatable by tri-chloracetic acid, thereafter commingling said heat treated cream and said thus-treated whey, and concentrating the resulting mixtureby evaporation.

3. The method of producing a heat treated fatcontaining bovine milk powder free from cooked or stale'flavors and capable of prolonged storage without development of rancidityjor of objectionable brown discoloration which comprise! heat treating cream at temperatures from about 200 to 300 F. for a time sufficient to stabilize the jet content thereof against rancidity, successively flowing through beds of resinous *decationizing and deacidifying media liquid whey containing lactose, ash forming constituents, acid, milk protein, and. complex milk protein derivative decomposition products forming part of the total assayable nitrogen of the material and thereby reducing the content of ash forming constituent! and the content of said decomposition products including peptides and free amino acids and determinable by formol titration, thereafter commingli-ng the heat treated cream and the thus treated whey, and concentrating and'drying the resulting mixture to a dried powder which is relativelystable, non-hygroscopic and easily dispersed.'

4. The method of preparing a heat treated fat-containing-miik product free from stale or cooked flavors and. capable of prolonged storage without discoloration'or development of rancidity which comprises heat treating a liquid milk fat concentrate at least to pasteurization temperatures for a time sufilcient'to stabilize the fat content thereof against rancidity, successively flowing through beds of resinous decationizlng and deacidifying media liquid whey containing lactose, ash 'forming constituents, acid, milk protein', and complex milk protein derivative decomposition products forming part of the total assayable nitrogen of the material and thereby reducing the content of ash forming constituents and the content of said decomposition products including peptides and free amino acids and determinable by formol titration, thereafter commingling said heat treated fat concentrate and the thus produced whey product, and heating the commingled mixture at least to pasteurization temperatures.

5. The method of preparing a stable heat treated boyine milk product suitable for infant feeding and free from cooked or stale flavors which comprises heat treating a fat concentrate of bovine milk at least to pasteurization temperatures 'for a period of time sufllcient to stabilize the fat content thereof against rancidity, contacting with 10 treated liquid whey is spray dried it forms a powder which is readily redispersible in water, REFERENCES CITED thereafter commingling said heat treated fat The following references are of record in the concentrate and said thus treated whey in a ratio l Of this p tent: I producing in the resulting mii ture the same pro- 5 UNITED STATES PATENTS portions of fat, lactose, casein proteln, non-casein protein, and ash present in human milk, Number Name ate concentrating the mixture by evaporation, and 985,271 Merlell 23, 1911 then drying the concentrate to form a powdered 1,341,040 BOSWOIth May 1920 product which is substantially non-hygroscopic 10 1,445,434 f' n r r F b. 3, 2 and readily dispersible in water. 1,714,597 Gr nd od May 28, 1929 1,801,152 Grasse Apr. 14, 1931 REGINALD MEADE, 2,072,903 Otting Mar. 9, 1937 PAUL D. CLARY, JR. 2,372,233 Thurston Mar. 27, 1945 1 2,383,070 Mook Aug. 21, 1945 2,404,367 Durant et a1 July 23, 1946 

